Coffee mug



FIG. 1 is a top perspective view of a coffee mug showing my new design;

FIG. 2 is a bottom plan view thereof;

FIG. 3 is a top plan view thereof;

FIG. 4 is a side view thereof;

FIG. 5 is an opposite side view thereof;

FIG. 6 is a frontal view thereof; and,

FIG. 7 is a rearward view thereof. 

The ornamental design for a coffee mug, as shown. 